// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// A BrowserPluginEmbedder handles messages coming from a BrowserPlugin's
// embedder that are not directed at any particular existing guest process.
// In the beginning, when a BrowserPlugin instance in the embedder renderer
// process requests an initial navigation, the WebContents for that renderer
// renderer creates a BrowserPluginEmbedder for itself. The
// BrowserPluginEmbedder, in turn, forwards the requests to a
// BrowserPluginGuestManager, which creates and manages the lifetime of the new
// guest.

#ifndef CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_
#define CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "content/public/browser/web_contents.h"
#include "content/public/browser/web_contents_observer.h"
#include "third_party/WebKit/public/platform/WebDragOperation.h"

struct BrowserPluginHostMsg_Attach_Params;

namespace content {

class BrowserPluginGuest;
class BrowserPluginGuestManager;
struct NativeWebKeyboardEvent;

class CONTENT_EXPORT BrowserPluginEmbedder : public WebContentsObserver {
public:
    ~BrowserPluginEmbedder() override;

    static BrowserPluginEmbedder* Create(WebContentsImpl* web_contents);

    // Called when embedder's |rwh| has sent screen rects to renderer.
    void DidSendScreenRects();

    // WebContentsObserver implementation.
    bool OnMessageReceived(const IPC::Message& message,
        RenderFrameHost* render_frame_host) override;

    // Sends a 'dragend' message to the guest that started the drag.
    void DragSourceEndedAt(int client_x, int client_y, int screen_x,
        int screen_y, blink::WebDragOperation operation);

    // Indicates that a drag operation has entered into the bounds of a given
    // |guest|. Returns whether the |guest| also started the operation.
    bool DragEnteredGuest(BrowserPluginGuest* guest);

    // Indicates that a drag operation has left the bounds of a given |guest|.
    void DragLeftGuest(BrowserPluginGuest* guest);

    // Called when the screen info has changed.
    void ScreenInfoChanged();

    // Closes modal dialogs in all of the guests.
    void CancelGuestDialogs();

    // Called by WebContentsViewGuest when a drag operation is started within
    // |guest|. This |guest| will be signaled at the end of the drag operation.
    void StartDrag(BrowserPluginGuest* guest);

    // Sends EndSystemDrag message to the guest that initiated the last drag/drop
    // operation, if there's any.
    void SystemDragEnded();

    // The page wants to update the mouse cursor during a drag & drop
    // operation. This update will be suppressed if the cursor is dragging over a
    // guest.
    bool OnUpdateDragCursor();

    // Used to handle special keyboard events.
    bool HandleKeyboardEvent(const NativeWebKeyboardEvent& event);

    // Find the given |search_text| in the page. Returns true if the find request
    // is handled by this browser plugin embedder.
    bool Find(int request_id,
        const base::string16& search_text,
        const blink::WebFindOptions& options);
    bool StopFinding(StopFindAction action);

    // Returns the "full page" guest if there is one. That is, if there is a
    // single BrowserPlugin in the embedder which takes up the full page, then it
    // is returned.
    BrowserPluginGuest* GetFullPageGuest();

    // Polls all guests for this web contents and returns true if any of them
    // were audible recently.
    bool WereAnyGuestsRecentlyAudible();

private:
    explicit BrowserPluginEmbedder(WebContentsImpl* web_contents);

    BrowserPluginGuestManager* GetBrowserPluginGuestManager() const;

    void ClearGuestDragStateIfApplicable();

    static bool DidSendScreenRectsCallback(WebContents* guest_web_contents);

    // Notifies a guest that the embedder's screen info has changed.
    static bool NotifyScreenInfoChanged(WebContents* guest_web_contents);

    // Closes modal dialogs in |guest_web_contents|.
    static bool CancelDialogs(WebContents* guest_web_contents);

    static bool UnlockMouseIfNecessaryCallback(bool* mouse_unlocked,
        WebContents* guest);

    static bool FindInGuest(int request_id,
        const base::string16& search_text,
        const blink::WebFindOptions& options,
        WebContents* guest);
    static bool StopFindingInGuest(StopFindAction action, WebContents* guest);

    static bool GuestRecentlyAudibleCallback(WebContents* guest);

    // Message handlers.

    void OnAttach(RenderFrameHost* render_frame_host,
        int instance_id,
        const BrowserPluginHostMsg_Attach_Params& params);

    // Used to correctly update the cursor when dragging over a guest, and to
    // handle a race condition when dropping onto the guest that started the drag
    // (the race is that the dragend message arrives before the drop message so
    // the drop never takes place).
    // crbug.com/233571
    base::WeakPtr<BrowserPluginGuest> guest_dragging_over_;

    // Pointer to the guest that started the drag, used to forward necessary drag
    // status messages to the correct guest.
    base::WeakPtr<BrowserPluginGuest> guest_started_drag_;

    // Keeps track of "dragend" state.
    bool guest_drag_ending_;

    base::WeakPtrFactory<BrowserPluginEmbedder> weak_ptr_factory_;

    DISALLOW_COPY_AND_ASSIGN(BrowserPluginEmbedder);
};

} // namespace content

#endif // CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_
